Elaborate circuit boards and manual assembly techniques are presently required to interconnect conventionally packaged R.F. and microwave components in hybrid circuits. Surface mount technology obviates these problems. Surface mounted components are compatible with automated assembly equipment, thereby avoiding the expense of manual assembly techniques. The surface mounted components also allow for enhanced assembly density. Surface mounted devices are rugged, and therefore can be used in commercial and military environments.
While surface mount digital ICs and passive devices have been in use for some time, the use of surface mount technology for R.F. and microwave components has been more difficult to realize. In R.F. and microwave applications, the transmission mediums and device interconnection behavior are of greater concern since they introduce inductance and capacitance which represents serious obstacles to system performance. In addition, a surface mount assembly places additional constraints on design because the assembly may have a different coefficient of thermal expansion than the printed wiring board material on which it is mounted.